A majority of workers in the Washington area now commute to jobs in jurisdictions other than where they live, according to census numbers to be released today.

Increasingly, people in virtually every local city and county are traveling across boundaries to work. Those who live in the District and its inner suburbs are more likely to commute to outer communities than they were a decade ago. And residents in the outer suburbs are also crossing county lines to get to jobs more than they did in the past.

Taken together, the statistics underscore the region's increasing mobility, with all that implies for worsening traffic congestion and less time at home. The 2000 Census results offer dramatic proof that traffic problems are the result not only of more cars on the road but also the longer distances those cars are traveling. The average commute time consumed two hours more each month than in the 1990s, other census figures show.

Just over half of the region's workers -- 1.4 million people -- commuted to jobs in other jurisdictions, becoming a majority since the 1990s. That compares with 1.3 million people who worked and lived in the same place in 2000. The number of Maryland residents commuting to Northern Virginia rose by more than 18,000, while the number of Virginians crossing the other way grew by 11,000.

Stephen Fuller, a professor at George Mason University who studies the regional economy, said the figures illustrate that job growth has been uneven across the region and that some people cannot afford to live near work. Northern Virginia added more jobs in the '90s than did Maryland.

The Washington region's increasing job sprawl, he said, makes it more difficult to live near work, especially for two-earner couples or other households with more than one worker.

"The sense is that the jobs have decentralized faster in the last decade than in previous decades," Fuller said. "There is no central location anymore."

The figures also indicate growth in reverse commuting: The District sends 3,000 more workers to Fairfax County each day than a decade ago. Fairfax exports 10,000 more workers to farther-out Loudoun County. Loudoun, because its population nearly doubled in size but its job base did not, sends an additional 18,000 workers back to Fairfax.

Transportation planner Ronald F. Kirby sees the trend play out each morning at the Braddock Road Metro station in Alexandria, where he gets on the inbound train for his job at the Metropolitan Washington Council of Governments in the District. These days, the outbound trains carry more people than they used to, many headed for jobs in Old Town.

"In some respects, that is kind of a good thing from a transportation point of view," Kirby said, noting that the Metro system has unused outbound seats during the morning rush hour.

The region's planners, Kirby said, are trying to ease congestion by encouraging commercial and residential construction near Metro stations. They also are promoting job growth in Maryland suburbs. Bus service has been added to Tysons Corner and other job centers, although some initiatives -- such as proposed rail service to the Dulles area -- are many years away.

For Mark Looney, the growth in reverse commuting means that he is sometimes better off not leaving his Reston office at 6 p.m. to go home to Arlington, but waiting until 7 p.m., when traffic clears. Still, he cannot see moving closer to work.

"It is a lifestyle choice to live closer to the city," said Looney, a single, 34-year-old land-use lawyer. "It is where my friends live."

In some jurisdictions, however, the share of residents who work and live in the same community stayed the same or increased, the census figures showed. Fairfax, Howard, Stafford and St. Mary's counties, which were job or population growth hot spots, saw their shares rise. Montgomery County held steady at 59 percent.

Other than the District, the communities that had the sharpest rise in the proportion of residents working elsewhere were Anne Arundel, Calvert and Fauquier counties. Anne Arundel sends a growing share of its working population to Baltimore and Howard counties, the numbers showed. The share of Calvert's commuters heading for St. Mary's more than doubled, echoing a boom in military employment there. And Fauquier exported more commuters to Fairfax and Prince William counties.

Database editor Dan Keating contributed to this report.

A recent morning rush on I-495 crawls. The census showed that the average commute consumed two more hours each month.GMU professor Stephen Fuller, who has studied the area economy, said some can't afford to live near work.I-395 during rush hour in Alexandria. Many trains are carrying workers from the city to Old Town, one planner said.